--- a/base/metrics/histogram.cc
+++ b/base/metrics/histogram.cc
@@ -94,6 +94,7 @@ class Histogram::Factory {
           uint32_t bucket_count,
           int32_t flags)
     : Factory(name, HISTOGRAM, minimum, maximum, bucket_count, flags) {}
+  virtual ~Factory() = default;
 
   // Create histogram based on construction parameters. Caller takes
   // ownership of the returned object.
@@ -741,6 +742,7 @@ class LinearHistogram::Factory : public
                          bucket_count, flags) {
     descriptions_ = descriptions;
   }
+  ~Factory() override = default;
 
  protected:
   BucketRanges* CreateRanges() override {
@@ -932,6 +934,7 @@ class BooleanHistogram::Factory : public
  public:
   Factory(const std::string& name, int32_t flags)
     : Histogram::Factory(name, BOOLEAN_HISTOGRAM, 1, 2, 3, flags) {}
+  ~Factory() override = default;
 
  protected:
   BucketRanges* CreateRanges() override {
@@ -1020,6 +1023,7 @@ class CustomHistogram::Factory : public
     : Histogram::Factory(name, CUSTOM_HISTOGRAM, 0, 0, 0, flags) {
     custom_ranges_ = custom_ranges;
   }
+  ~Factory() override = default;
 
  protected:
   BucketRanges* CreateRanges() override {
--- a/base/metrics/statistics_recorder.h
+++ b/base/metrics/statistics_recorder.h
@@ -67,6 +67,7 @@ class BASE_EXPORT StatisticsRecorder {
   // histograms from providers when necessary.
   class HistogramProvider {
    public:
+    virtual ~HistogramProvider() {}
     // Merges all histogram information into the global versions.
     virtual void MergeHistogramDeltas() = 0;
   };
--- a/base/bind_unittest.cc
+++ b/base/bind_unittest.cc
@@ -69,6 +69,7 @@ static const int kChildValue = 2;
 
 class Parent {
  public:
+  virtual ~Parent() {}
   void AddRef() const {}
   void Release() const {}
   virtual void VirtualSet() { value = kParentValue; }
@@ -78,18 +79,23 @@ class Parent {
 
 class Child : public Parent {
  public:
+  ~Child() override {}
   void VirtualSet() override { value = kChildValue; }
   void NonVirtualSet() { value = kChildValue; }
 };
 
 class NoRefParent {
  public:
+  virtual ~NoRefParent() {}
   virtual void VirtualSet() { value = kParentValue; }
   void NonVirtualSet() { value = kParentValue; }
   int value;
 };
 
 class NoRefChild : public NoRefParent {
+ public:
+  ~NoRefChild() override {}
+ private:
   void VirtualSet() override { value = kChildValue; }
   void NonVirtualSet() { value = kChildValue; }
 };